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Towards the study of the Solar wind Effects on the Magnetosphere using Fully Kinetic Simulations. Jorge AMAYA 1 , Jan DECA 1 , Stefano Markidis 2 , Andrei DIVIN 3 , Bertrand Lembège 4 , Giovanni LAPENTA 1 1 CPA, KULeuven, Belgium
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Towards the study of the Solar wind Effects on the Magnetosphere using Fully Kinetic Simulations Jorge AMAYA1, Jan DECA1, Stefano Markidis2, Andrei DIVIN3, Bertrand Lembège4, Giovanni LAPENTA11CPA, KULeuven, Belgium 2KTH Royal Institute of Technology, Sweden3Institutet för rymdfysik, Uppsala Universitet, Sweden4LATMOS, CNRS, France
EU FP7 projects • SWIFF: Space Weather Integrated Forecasting Framework (n° 263340) • eHeroes: Environment for Human Exploration and RObotic Experimentation in Space (n° 284461) • DEEP: Dynamical Exascale Entry Platform (n° 287530)
Motivation: Space Weather • Complex plasma physics • From fluid to kinetic effects • From electron to planetary scales • Highly coupled phenomena • Effects on human and robotic space exploration
Numerical methods [1] University of Alberta web page. [2] N. Omidi et al., Advances in Space Research, Volume 38, Issue 4, 2006 [3] Toseo Moritaka, et al., Phys. Plasmas 19, 032111, 2012
Fully kinetic [1] S. Baraka and L. Ben-Jaffel, Ann. Geophys., 29, 2011 Density Magnetic field
PiC simulations at ion-scales [1] M. Matsumoto et al., Plasma and Fusion Research, 8, 2013 • Adaptative mesh refinemet. • Ion-scale simulation: applications to spacecraft shielding and magnetic sails
Global 3D PiC [1] Cai et al., Earth Planets Space, 53, 2001 Global magnetospheric 3D topology
Hybrid-Vlasov codes • Solving above ion scales. • Capture of wave propagation in the foreshock and the magnetosheat. • Resolution in spatial (2D) and velocity (3D) spaces.
Tha Particle-in-Cell method PARTICLES FIELDS Interpolation
Implicit equations Particles: Fields: Stability condition:
Advantages of the iPic3D code • Self-consistent. • Implicit methods allow a wider range of time and space scales • Highly scalable: improves with technology which makes it perfect for ExaScale systems • Simple enough to port to new architectures
Disadvantages of the PiC method • Particle noise: requires higher resolution. • Boundary conditions: requires improved numerical methods. • CPU cost: requires to work on new architectures and better algorithms. • Problem size: coupled and multi-domain algorithms are being developed.
Current objectives • Simulation parametters closer to the actual physics. • 3 types of simulations: • A. 2D Noon-Midnight meridian plane • B. 2D Equatorial plane • C. 3D
A. Noon-midnight meridian plane Reconnection Text
A. Noon-midnight meridian plane IMF Particle absorbing body Magnetic dipole Solar wind
B. Equatorial plane Diffusion effects at the boundary layer Text [1] T. D. Phan and G. Paschmann, J. Geophys. Res., 101, 7801, (1996).
B. Equatorial plane: density Simulation initialization 15 000 cycles,7 hours,1024 processors, 1.7 Mcells, 88.5 Mparticles
Comparison against an hybrid code [1] J. Paral and R. Rankin, Nature Communications, 4 - 1645, April, 2013
B. Across the shock • 4 zones: • Interplanetary plasma • Magnetosheat • Diffusion zone • Magnetosphere • Top: ion density • Bottom: ion density and magnitude of the magnetic field
B. Dusk density profiles • Density variation across the magnetosheat • Sharp density drop across the magnetopause • Instabilities in the plasma flow at the magnetopause
C. Future work • Higher resolution • Bigger planet • Fully implicit • Computations with up to 100 000 CPU cores • Improvement of boundary conditions • 3D system
Conclusions • PiC methods are very sensitive to the thermal velocities imposed. • Global simulations with electron-scale resolutions are yet computationally expensive. • Boundary conditions are a major issue. • We are pushing the code to the current computational limits. • However we are currently performing simulations with parametters very close to those measured in-situ.
Towards the study of the Solar wind Effects on the Magnetosphere using Fully Kinetic Simulations Jorge AMAYA1, Jan DECA1, Stefano Markidis2, Andrei DIVIN3, Bertrand Lembège4, Giovanni LAPENTA11CPA, KULeuven, Belgium 2KTH Royal Institute of Technology, Sweden3Institutet för rymdfysik, Uppsala Universitet, Sweden4LATMOS, CNRS, France
The iPiC3D code (x, y, z) (u, v, w) (Bx, By, Bz) (Ex, Ey, Ez)
Second order Maxwell Taylor series expansion of the shape function: Applying to the moments gives a linear interpolation: { where
Final form for the E field equation Stability condition: